Refrigeration system



Feb. 28, 1967 w. M. REID 3,306,062

REFRIGERATION SYSTEM Filed Aug. 18, 1965 W/ ///0/77 M fie/a 1N VENTOR.

BY Magda (9 Rune)? T TOR NE YS United States Patent 3,306,062 REFRIGERATION SYSTEM William M. Reid, 4747 W. Alabama, Houston, Tex. 77027 Filed Aug. 18, 1965, Ser. No. 480,639 5 Claims. (CI. 6288) The present invention relates to new and useful improvements in refrigeration systems and more particularly, to a refrigeration system using a single fluid for motive power and also for the refrigerant.

Heretofore, with refrigeration systems of the compressor-condenser-expander type, various efforts have been made to cool the compressor exhaust so as to reduce the load on the condenser; however, cooling the compressor exhaust reduces the overall efficiency of the refrigerator system, thus a second problem is created in attempting to solve the first. With the present invention, a single fluid is employed both as the working fluid to operate the prime mover that drives the compressor and also as the refrigerant so that heat from the compressor exhaust may be back exchanged or transferred to the working fluid that operates the prime mover so that at least a part of the heat from the compressor exhaust may be salvaged and thus reduce the overall motive heat requirements for the system.

An object of the present invention is to provide a new and improved refrigeration system using a single fluid for the working fluid to operate an expansion engine to drive a refrigerant compressor and also for the refrigerant that is used for cooling in the refrigerating system.

Another object of the present invention is to provide a new and improved integrated refrigeration system using a single fluid as both a refrigerant and working fluid to operate a refrigerant compressor wherein heat from the compressor exhaust is transferred to the portion of the working fluid which operates the compressor.

Still another object of the present invention is to provide a new and improved refrigeration system of the compressor-condenser-expander type having a turbine to drive the compressor wherein heat from the turbine exhaust and heat from the compressor exhaust are commingled and exchanged with the portion of the working fluid which operates the turbine to reduce the condenser heat load.

Another object of the present invention is to provide a new and improved refrigeration system having a compressor, a condenser and an evaporator employing a single fluid for both motive power and refrigerant wherein the turbine exhaust and compressor discharge are commingled and exchanged with the working fluid that operates the turbine and wherein fluid discharged from the evaporator is heated 'before entering the compressor to produce a more eflicient refrigeration system.

The preferred embodiment of this invention will be described hereinafter, together with other features thereof, and additional objects will become evident from such description.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:

The figure in the attached drawing is a schematic presentation of the flow diagram of the method and apparatus of the present invention in association with a standard compressor-condenser-expander type refrigeration system.

The attached diagrammatic drawing illustrates one form of the refrigeration system of the present invention which includes a refrigeration circuit designated generally R and a power or prime mover circuit designated generally M. The refrigeration system of this invention uses a single fluid such as propane, Freon or ammonia or the like as the power medium in the power circuit M and also as the refrigerant in the refrigerating circuit R. As shown in the drawing, the refrigeration circuit portion R of this invention includes a compressor C, a condenser K, and an evaporator E which are connected together in a normal manner as will be described in detail hereinafter. Also shown in the drawing are a pump P, a primary heater or furnace F, a turbine or expansion engine T, and a heat exchanger H which together comprise the motive power circuit M that operates the refrigeration circuit R of the present invention.

Considering now the refrigeration system of this invention in more detail, the compressor C has a discharge conduit 10 and the turbine T has a discharge or exhaust conduit 11, both of which are connected to a pipe or tube 12. The turbine exhaust which is normally superheated and the hot compressor eflluent thus introduced into line 12 are intermixed therein and are conducted to the heat exchanger H. Heat from the superheated fluid in the conduit 12 is transferred in the heat exchanger H to the working fluid which is being conducted to the furnace or primary heater F as will be explained in detail hereinafter. After being partially cooled in the heat exchanger H, the intermixed fluid is then conducted via a conduit 13 from the heat exchanger H to the condenser K were such fluid is condensed in the normal manner. After being cooled and condensed to a liquid form in the condenser K, such fluid is then conducted through a suitable conduit 15 to a refrigeration surge tank 17 which is provided for storing the liquid refrigerant. A suitable conduit 18 is provided for conducting liquid refrigerant from the surge tank 17 to the evaporator E where the liquid refrigerant is greatly expanded in a manner well known in the art for cooling.

After being expanded in the expansion device E, the gaseous mixture or fluid is then conducted through the pipe or conduit 21 back to the compressor C where such gaseous fluid is compressed and recirculated in the refrigeration circuit R. An additional or supplemental heater F may be provided in the circuit 21 between the evaporator E and the compressor C for heating fluid before it enters the compressor C and thereby improve overall system efliciency. However, although such supplemental heater F is desirable and improves efliciency, it may be omitted, if desired.

The pump P is shown connected to the liquid refrigerant line 18 by means of a suitable conduit 23, or such line 23 may be connected directly to the refrigerant tank 17. The pump P is preferably mounted on a common shaft 22 with the expansion engine or turbine T and the compressor C with all such components hermetically sealed in a single case or housing (not shown). The pump discharge is conducted via a conduit 25 to the heat exchanger H where liquid refrigerant pumped by the pump is preheated by heat that is transferred from the intermixed superheated vapor carried in the line 12 from the turbine T and the compressor C.

After being preheated in the heat exchanger H, the fluid from the pump P is conducted through a suitable conduit 26 to the furnace or primary heater F in which such fluid is superheated prior to being introduced into the expansion engine T. In the preferred form of this invention, suflicient heat is applied to the fluid in the heater F to produce a superheated vapor for operating the turbine T, and such heated vapor discharges into the exhaust line 11 for thereafter mixing with the vapor discharged into line 10 from the compressor C, whereby such intermixed heated vapors flow to the heat exchanger H as explained hereinbefore.

Thus, it will be appreciated that with the method and apparatus of the present invention, a substantial amount J of the heat in the hot exhaust from the compressor C is transferred to the working fluid and thus salvaged to provide a refrigeration system of greatly improved efficiency.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made Within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. A method of operating a refrigerating system having compressor, condenser, and evaporator stages and wherein a compressor for the compressing stage is operably connected to an expansion engine, the improvement residing in the steps of:

(a) circulating system;

(b) diverting a portion of the liquid refrigerant from the condenser stage of the refrigeration system;

(c) elevating the pressure of such diverted portion of liquid refrigerant;

(d) thereafter heating such diverted portion of the liquid refrigerant; and

(e) expanding such heated liquid portion in the expansion engine of the refrigerating system for driving same to operate the compressor for compressing the refrigerant in said refrigeration system.

2. The steps of claim 1 and including the steps of:

(a) cornmingling the hot exhaust stream from the exa refrigerant in the refrigeration pansion engine with the exhaust stream from the compressor; and

(b) preheating the portion of liquid refrigerant diverted from the condenser of the refrigeration cycle by exchanging heat from said commingled exhaust streams therewith.

3. The steps of claim 1 and including the step of exchanging heat from the expansion engine exhaust with the diverted liquid refrigerant portion to preheat such diverted liquid portion after elevating the pressure and prior to the heating of such portion.

4. The steps of claim 1 and including the step of exchanging heat from the compressor exhaust with the diverted liquid refrigerant portion to preheat such diverted liquid portion after elevating the pressure and prior to the heating of such portion.

5. The steps of claim 4 and including the step of heating the exhaust from the evaporator stage prior to its entering the compressor stage of the refrigeration system.

References Cited by the Examiner UNITED STATES PATENTS WILLIAM J. WYE, Primary Examiner. 

1. A METHOD OF OPERATING A REFRIGERATING SYSTEM HAVING COMPRESSOR, CONDENSER, AND EVAPORATOR STAGES AND WHEREIN A COMPRESSOR FOR THE COMPRESSING STAGE IS OPERABLY CONNECTED TO AN EXPANSION ENGINE, THE IMPROVEMENT RESIDING IN THE STEPS OF: (A) CIRCULATING A REFRIGERANT IN THE REFRIGERATION SYSTEM; (B) DIVERTING A PORTION OF THE LIQUID REFRIGERANT FROM THE CONDENSER STAGE OF THE REFRIGERATION SYSTEM; (C) ELEVATING THE PRESSURE OF SUCH DIVERTED PORTION OF LIQUID REFRIGERANT; (D) THEREAFTER HEATING SUCH DIVERTED PORTION OF THE LIQUID REFRIGERANT; AND (E) EXPANDING SUCH HEATED LIQUID PORTION IN THE EXPANSION ENGINE OF THE REFRIGERATING SYSTEM FOR DRIVING SAME TO OPERATE THE COMPRESSOR FOR COMPRESSING THE REFRIGERANT IN SAID REFRIGERATION SYSTEM. 